[PATCH]fix page release issue in filemap_fault

[PATCH]fix page release issue in filemap_fault

[Yan Zheng]

Hi all

find_lock_page increases page's usage count, we should decrease it
before return VM_FAULT_SIGBUS

Signed-off-by: Yan Zheng<yanzheng@21cn.com>
----
diff -ur linux-2.6.23-rc9/mm/filemap.c linux/mm/filemap.c
--- linux-2.6.23-rc9/mm/filemap.c	2007-10-07 15:03:33.000000000 +0800
+++ linux/mm/filemap.c	2007-10-08 23:14:39.000000000 +0800
@@ -1388,6 +1388,7 @@
 	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 	if (unlikely(vmf->pgoff >= size)) {
 		unlock_page(page);
+		page_cache_release(page);
 		goto outside_data_content;
 	}

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH]fix page release issue in filemap_fault

[Peter Zijlstra]

On Mon, 2007-10-08 at 23:28 +0800, Yan Zheng wrote:
> Hi all
> 
> find_lock_page increases page's usage count, we should decrease it
> before return VM_FAULT_SIGBUS
> 
> Signed-off-by: Yan Zheng<yanzheng@21cn.com>

Nice catch, .23 material?

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

> ----
> diff -ur linux-2.6.23-rc9/mm/filemap.c linux/mm/filemap.c
> --- linux-2.6.23-rc9/mm/filemap.c	2007-10-07 15:03:33.000000000 +0800
> +++ linux/mm/filemap.c	2007-10-08 23:14:39.000000000 +0800
> @@ -1388,6 +1388,7 @@
>  	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
>  	if (unlikely(vmf->pgoff >= size)) {
>  		unlock_page(page);
> +		page_cache_release(page);
>  		goto outside_data_content;
>  	}

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH]fix page release issue in filemap_fault

[Rik van Riel]

On Mon, 08 Oct 2007 19:15:23 +0200
Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, 2007-10-08 at 23:28 +0800, Yan Zheng wrote:
> > Hi all
> > 
> > find_lock_page increases page's usage count, we should decrease it
> > before return VM_FAULT_SIGBUS
> > 
> > Signed-off-by: Yan Zheng<yanzheng@21cn.com>
> 
> Nice catch, .23 material?

An obvious fix for a memory leak.  I think it should go in.

> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

Acked-by: Rik van Riel <riel@redhat.com>

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>